TIBURON, CALIFORNIA—Tiburon, a small but wealthy town just northeast of the Golden Gate Bridge, has an unusual distinction: it was one of the first towns in the country to mount automated license plate readers (LPRs) at its city borders—the only two roads going in and out of town. Effectively, that means the cops are keeping an eye on every car coming and going.

A contentious plan? Not in Tiburon, where the city council approved the cameras unanimously back in November 2009.

The scanners can read 60 license plates per second, then match observed plates against a "hot list" of wanted vehicles, stolen cars, or criminal suspects. LPRs have increasingly become a mainstay of law enforcement nationwide; many agencies tout them as a highly effective "force multiplier" for catching bad guys, most notably burglars, car thieves, child molesters, kidnappers, terrorists, and—potentially—undocumented immigrants.

Today, tens of thousands of LPRs are being used by law enforcement agencies all over the country—practically every week, local media around the country report on some LPR expansion. But the system's unchecked and largely unmonitored use raises significant privacy concerns. License plates, dates, times, and locations of all cars seen are kept in law enforcement databases for months or even years at a time. In the worst case, the New York State Police keeps all of its LPR data indefinitely. No universal standard governs how long data can or should be retained.

Not surprisingly, the expanded use of LPRs has drawn the ire of privacy watchdogs. In late July 2012, the American Civil Liberties Union and its affiliates sent requests to local police departments and state agencies across 38 states to request information on how LPRs are used.

As I headed into the picturesque town last month for a meeting with local police, I kept a lookout for the LPRs. Tiburon Boulevard, along the city's southern coastal edge, is a lovely stretch of road overlooking a small bay that feeds into the San Francisco Bay. On summer days, cyclists and runners take to a trail along the water's edge. And It was there that I spotted the cameras, mounted on a traffic island just west of the intersection with Blackfield Drive.

Cameras point in each direction of traffic, each one trained on two lanes. The LPRs, with their sleek cylindrical design, look similar to a surveillance camera or a speed camera. They provide no indication of what they do, nor would you know by looking that have become the newest object of contention in the long-running war between "security" and "privacy." But as I drove into town to interview Captain David Hutton and Chief Michael Cronin of the Tiburon Police Department, the cameras did their silent work: my plate was scanned, parsed, and logged in the name of security.

I met Capt. Hutton in a police conference room; Chief Cronin, recovering at home after surgery, joined us by phone. First, the officers made the case that LPRs really do provide more security to towns like Tiburon. After we hung up with Chief Cronin, Capt. Hutton obligingly showed me the database entries for my own arrival.

Four of Tiburon's six LPRs are mounted on Tiburon Boulevard, near Blackfield Drive.

Cyrus Farivar

Hitting the hot list

The entire LPR setup, including the six new cameras, cost $130,000. Funding came in part from the Marin County Sheriff's Department and the adjacent City of Belvedere; as a result, those other entities also get access to the Tiburon camera data.

The cameras run constantly, looking for hot listed plates. When they spot one, the system sends automated alerts directly to officers' in-car and in-office computers and to the Marin County Sheriff's communications desk (which does dispatching for Tiburon). The alerts provide a photo of the car in question, the date, the time, and which specific camera spotted the car.

Help us watch the watchers

In the course of this story, Ars e-mailed the state law enforcement agencies of all 50 states to learn more about how LPRs are used; we received replies from just a handful. We followed up with FOIA and public information requests asking for LPR purchase orders, privacy guidelines, and other documents from ten state, ten local, and three federal agencies, including the FBI, the DEA, and Customs and Border Protection.

We learned, for example, that the Bismarck, North Dakota Police Department and the Hawaii State Police both deny using LPRs at all. The Delaware State Police, meanwhile, says it owns three readers. After a month, we've had relatively few responses, though many of the requests are still pending.

Cronin explained that in a town like Tiburon, where the biggest criminal concern is property crime, knowing who is coming and going at odd hours has been very helpful to the squad. The chief added that, prior to deploying the cameras, crime was still relatively low—only about 100 to 120 thefts per year, he said. Since the cameras have been in place, that figure has dropped by "around a third," he said.

However, the system is not without flaws. It tends to yield numerous false positives because the hot list data received from the California Department of Motor Vehicles takes a long time to be updated—and because the system cannot distinguish out-of-state plates. This creates a problem if, for instance, California plate ABC123 has been reported as stolen and is on the hotlist, and then someone drives through Tiburon with Oregon plate ABC123. (Other LPR systems can distinguish the plates from different states.)

Hutton showed me an example of a unique California vanity plate that the department gets a hit on every day, because that same plate from a different state was reported stolen. The Tiburon authorities pulled over the local resident once, his story checked out, but his plate turns up again every time he enters or leaves the city.

In addition, the cameras miss some plates. When I saw the LPR system, for instance, I slowed down to get a better look. By the time I reached Blackfield Drive, I knew I had to turn around to get closer, so I made a U-turn and pulled over in the shoulder directly across from the cameras. I parked my car, and walked over to the island to snap a few pictures with my phone. I got back in my car, drove ahead 20 feet or so while still on the shoulder, and then moved over to the left turn lane, making a second U-turn to head back toward the police station. When I asked Capt. Hutton to see my own log entry, the camera had only recorded my inbound entries. Pulling over to the shoulder apparently put me out of range of the camera—a pretty easily exploitable weakness. I'd "hacked" the Tiburon Police LPRs without even trying.

Even when the cameras do score a "hit" against the hot list, few are linked to major crimes. "The vast majority of the hits that we get are not wanted cars, they're lost or stolen plates," said Cronin.

And he recognizes the system's easy susceptibility to abuse. "We could put our boss's plates in the system and every time she leaves town we could go get her golf clubs," he joked.

To prevent problems, only Cronin and Hutton can add plates to the hot list. Each time a plate is run for historical data by either an officer or requested by an outside agency, the requester has to inform the chief by e-mail. Requests are tallied in an annual report for the town council.

A multi-million dollar industry

LPR systems are doing big business at the moment. The country's largest such company, Federal Signal Corporation (FSC), which sells LPRs under its PIPS brand name, says it has sold 20,000 mobile systems across North America and another 15,000 fixed devices across the United States and the United Kingdom.

"We work with the 25 largest cities in the United States, over 100 cities in the US and over 200 in North America, including the Royal Canadian Mounted Police and in Mexico," said Tim O'Leary, a company vice president, in an interview with Ars. "We think the market is growing at 8 to 10 percent, adjusted growth rate, annually."

In its SEC filing earlier this year, FSC said its sales of LPRs were up by $2.1 million in 2010 alone. One of its primary competitors, Elsag North America, says it has worked with 1,200 agencies nationwide, while declining to state how many LPRs it has sold.

The New York Police Department began using LPR devices made by Elsag in 2006. As of 2011, the NYPD told the New York Times that it maintains 108 stationary LPRs and 130 mobile devices (Elsag's "Mobile Plate Hunter".)

The Times also wrote that in 2005, the year before LPRs were introduced, New York City had nearly 18,000 reports of stolen cars, a figure that fell to just over 10,000—a drop of over 40 percent—in the next six years. The NYPD attributes the benefits of LPR technology to being "directly responsible" for recovering over 3,600 stolen cars and for issuing summons to nearly 35,000 unregistered vehicles.

In September 2011, the FBI reported that its Criminal Justice Information Services Advisory Policy Board (CJIS APB) had approved the use of LPRs years earlier through a pilot project conducted by the Ohio State Highway Patrol. That pilot has since expanded to "46 states, the District of Columbia, 33 local agencies, and one federal agency," which have "formal agreements with the FBI to receive the [National Crime Information Center] information for the purpose of using LPRs."

The FBI also added that a survey of its pilot partners "reported a total of 1,102 stolen vehicles recovered with a value of more than $6.5 million, as well as contraband recovered that included stolen license plates, stolen property, vehicles, drugs, weapons, larceny proceeds, suspended registrations, credit cards, and a police badge. Also as a result of the LPR technology, participating agencies located 818 subjects listed in the Wanted Persons File and 19 listed in the Missing Persons File. Another 2,611 persons were apprehended."

The recent uptick in LPR deployments is likely due to a combination of price drops—each camera can cost between $8,000 and $20,000 now—and increased federal grants for the tech. Various agencies, in particular the Department of Homeland Security, the Drug Enforcement Agency, and Customs and Border Protection have issued many millions of dollars in federal grants to state and local law enforcement to buy the hardware. (Both FSC and Elsag provide prominentlinks on their websites to help cops apply for these grants, too.)

> at this time there is no decisional case law from any court concerning the use of a license plate reader

Why do lawyers have to make up words? "Decisional"? Decisive works really well there.

And, no, don't get me started about the abuse of "societal" when people really are describing something "social."

Or burglarize for burgle ... hey, you, get off my damn lawn!

OT: I think it's interesting that people don't object much to the scanners themselves but to the maintenance of long-term databases. It's a surprising twist to the usual response to things like traffic cameras, etc.

What about people who alter their plates in an effort to avoid tolls, or LPR. It is easy enough to do, change a L or F to an E , or alter a T into an I. As with anything it's not foolproof.

That, of course, is illegal. But thanks for the tip! Seriously, I would think repetitive "misses" (bills getting sent to the wrong person or not found in db) would alert someone who would take notice. Also, if a cop sees that, well, bad news.

What about people who alter their plates in an effort to avoid tolls, or LPR. It is easy enough to do, change a L or F to an E , or alter a T into an I. As with anything it's not foolproof.

But Big Brother has been watching, and will continue to do so.

Someone sent me an ad for two products designed to prevent red light cameras from capturing plate numbers. One was a clear spray, and the other a plastic cover attached to a license plate frame. Apparently they worked by creating a glare that prevented the camera from capturing a readable image.

I didn't try these (I quit running red lights in my younger days), but it would be sort of funny if a $10 spray or $20 license plate cover could render a $100K+ system ineffective.

1. Legally, a team of agents can follow you around in public and record your every move. Our new networked sensors and databases are the same thing, just more efficient. Therefore we should be allowed to record everything that everyone does in public.

2. If you videotape one of us in public we will confiscate your camera and arrest you.

If a license plate is not on the hot-list, not a stolen car, not associated to any criminal reports, not related to any known terrorist activity, not associated with any outstanding police issues, and not related to illegal immigrants, why would it be stored in the police database? If it's clean, dump the data as it is completely irrelevant to the business of police, which is track down criminal activity.

surprised they don't try to use facial data too to cross reference peoples faces for crimes, oh how Facebook would get a sweet check if they made a backroom deal with state governments on integrating their facial recognition software with state camera systems. I'm sure nobody would mind that

Someone sent me an ad for two products designed to prevent red light cameras from capturing plate numbers. One was a clear spray, and the other a plastic cover attached to a license plate frame. Apparently they worked by creating a glare that prevented the camera from capturing a readable image.

I didn't try these (I quit running red lights in my younger days), but it would be sort of funny if a $10 spray or $20 license plate cover could render a $100K+ system ineffective.

Police departments will claim those products don't work, but have also made them illegal in many states.

Technically everything someone does in public is public information, so lets just create a giant online open database that tracks everything that everyone does and makes it all public information.

A: "Why did you come home so late?"B: "Oh I had so much work I couldn't leave the office!"A: "Why did a charge by XSC LTD appear on the Visa today?"B: "Since I couldn't leave the office, I was doing some online shopping for our anniversary!"

To be extremely useful, the data should be public loaded onto a website to allow citizens to track the movements of all city officials and workers during the work day. This should include all police officers/fire marshals who have "drive home" priveleges.

If a license plate is not on the hot-list, not a stolen car, not associated to any criminal reports, not related to any known terrorist activity, not associated with any outstanding police issues, and not related to illegal immigrants, why would it be stored in the police database? If it's clean, dump the data as it is completely irrelevant to the business of police, which is track down criminal activity.

Each time a plate is run for historical data by either an officer or requested by an outside agency, the requester has to inform the chief by e-mail. Requests are tallied in an annual report for the town council.

LOL, what could possibly go wrong here...

Seriously, $130,000 and no proper (i.e. tamper-resistant) logging and auditing features? Or do these exist and they just chose not to enable them?

> at this time there is no decisional case law from any court concerning the use of a license plate reader

Why do lawyers have to make up words? "Decisional"? Decisive works really well there.

The fact that you have a poor vocabulary doesn't mean words you don't know are made up.

Ah, a new poster. And so keen to commit ad hominem attacks out of the blocks! Please note the end clause in the overall set was meant to indicate that some graybearding was going on. And, I'll be sure to tell my university students, and my publisher, to make sure I enrich my vocabulary. Somewhere I must've slipped in the 3000-word base vocabulary for English. Maybe I'm stuck at the 1000-word base for some of the romance languages? Clearly, I'm nowhere near the 10,000 words for Shakespeare.

What about people who alter their plates in an effort to avoid tolls, or LPR. It is easy enough to do, change a L or F to an E , or alter a T into an I. As with anything it's not foolproof.

But Big Brother has been watching, and will continue to do so.

Someone sent me an ad for two products designed to prevent red light cameras from capturing plate numbers. One was a clear spray, and the other a plastic cover attached to a license plate frame. Apparently they worked by creating a glare that prevented the camera from capturing a readable image.

I didn't try these (I quit running red lights in my younger days), but it would be sort of funny if a $10 spray or $20 license plate cover could render a $100K+ system ineffective.

In many states, you can't put a cover over your license plate. Regarding the sprays, there are some youtube videos of newscasts where it was determined that the sprays did work. However, I believe there is a simple optical countermeasure to get around the spray. The spray just makes the plate more reflective. However, if the camera uses a polarized light source and a polarizer on the lens, that is a matched polarity optical systems, the effect of the glare can be reduced. The light source could be infrared.

Regarding Tiburon, there is one road into town. You go to Tiburon, they got your plate. Tiburon is a bit of a tourist trap since the ferry to Angel Island is based there.

Some towns in Nevada routinely run every plate at the local motels. People on the run will often stay at some obscure motel in a desert town. So running plates en mass isn't anything new. But the police have the "color of authority." But private companies shouldn't be able to sell what data they obtain IF the camera is placed on public property.

Regarding license plate readers on private property, it is THEIR property. Property owners have rights. But I think a good law would be that the camera has to be marked, and a sign must be displayed if they release the plate numbers read to third parties. Berkeley requires signage if you have surveillance cameras on your property.

Lastly, may I point out that the security patrols around Groom Lake (Area 51) routinely drive on public roads without plates on their trucks. There are numerous photos on the internet showing this. If I am required to have a license plate, then the men in black, or in the case of Groom Lake secuirty, camo, should have plates as well.

1. Legally, a team of agents can follow you around in public and record your every move. Our new networked sensors and databases are the same thing, just more efficient. Therefore we should be allowed to record everything that everyone does in public.

2. If you videotape one of us in public we will confiscate your camera and arrest you.

Sadly, this.

Now that the majority of people have a camera on them at any given moment, it could help usher in an age of actual accountability for the police. So of course they're going to fight that tooth and nail.

Someone sent me an ad for two products designed to prevent red light cameras from capturing plate numbers. One was a clear spray, and the other a plastic cover attached to a license plate frame. Apparently they worked by creating a glare that prevented the camera from capturing a readable image.

I didn't try these (I quit running red lights in my younger days), but it would be sort of funny if a $10 spray or $20 license plate cover could render a $100K+ system ineffective.

I think you might be able to legally get away with altering your plates if you capatch the hell out of it, so maybe a T is still a T but you shave some of the display off to make it more like a 7 and maybe the F is a 1 but with two floating : next to it, looking at it, would make it look like a worn plate maybe from a fender bender

Considering that they need evidence of a crime being committed before they can search or seize, they shouldn't be able to do this. Furthermore, I think that all license plates that are not involved in a crime should not even be made as an entry in their database, because that is akin to gathering evidence despite the absence of a crime.

Considering that they need evidence of a crime being committed before they can search or seize, they shouldn't be able to do this. Furthermore, I think that all license plates that are not involved in a crime should not even be made as an entry in their database, because that is akin to gathering evidence despite the absence of a crime.

There is a public benefit to having this data available. Most crimes are reported in 24 hours. The data should be deleted unless flagged by law enforcement (for archive) within 48 hours of recording or unless flagged based on rules setup by law enforcement (which should be based on reasonable suspicion).

They're looking for actual criminals today. But, once they're allowed to do this for a while, they'll start tracking suspects, too. Someone hasn't been convicted of a crime, no warrant for their arrest. But, they're a "person of interest". That person is going to get stalked by the cops. And while police are nice to you when you haven't done anything wrong, when you're a suspect you can get treated like you're guilty and some officers can get down-right nasty.

Also funny that it somehow costs $100,000 for a video camera and a simple program to pull frames with license plates and run character recognition.

On the topic of price for the system, making software to identify the plate, pull the letter and number combination based on the angle, and actually get it right with a fair amount of accuracy (I'm assuming not even a government agency would bother buying something that didn't work) is not as easy to do as it sounds. As likely anyone involved in software development (or any industry for that matter) knows, most things take at least 2 times as long to do as you expect them to, often times far longer. It's why so many software projects fail or come in over budget.

On the topic at hand however, I do think that there should be some sort of governing rules on how long data should be kept. Having my license plate read when I head into a town and leave from it doesn't seem to be that much of a violation of privacy, after all they could position a police officer on the road to do the same thing. The idea that those records are then stored forever (such as in NYC) seems unnecessary.

In many states, you can't put a cover over your license plate. Regarding the sprays, there are some youtube videos of newscasts where it was determined that the sprays did work. However, I believe there is a simple optical countermeasure to get around the spray. The spray just makes the plate more reflective. However, if the camera uses a polarized light source and a polarizer on the lens, that is a matched polarity optical systems, the effect of the glare can be reduced. The light source could be infrared.

I'm wondering if you could mount a few high intensity IR LEDs somewhere around the license plate, say, in a license plate frame, or strategically mounted in the mounting screws... Since most cameras now are CCD, and can pick up IR as a big splotch of light... If they are bright enough, I wonder if they would obscure the plate, or at least partially obscure it?

Those results have to do with speed cams. They have nothing to do with LPRs. They need to do another show to see how well they work and how to fool them.

If they did, they'd be leaned on pretty hard by the legal department at Discovery to not air anything that shows you how to really do it. Plus, they wouldn't want to jeopardize the relationships they've fostered with law enforcement groups that let them do things with high explosives all the time.

What about people who alter their plates in an effort to avoid tolls, or LPR. It is easy enough to do, change a L or F to an E , or alter a T into an I. As with anything it's not foolproof.

But Big Brother has been watching, and will continue to do so.

Someone sent me an ad for two products designed to prevent red light cameras from capturing plate numbers. One was a clear spray, and the other a plastic cover attached to a license plate frame. Apparently they worked by creating a glare that prevented the camera from capturing a readable image.

I didn't try these (I quit running red lights in my younger days), but it would be sort of funny if a $10 spray or $20 license plate cover could render a $100K+ system ineffective.

In many states, you can't put a cover over your license plate. Regarding the sprays, there are some youtube videos of newscasts where it was determined that the sprays did work. However, I believe there is a simple optical countermeasure to get around the spray. The spray just makes the plate more reflective. However, if the camera uses a polarized light source and a polarizer on the lens, that is a matched polarity optical systems, the effect of the glare can be reduced. The light source could be infrared.

Regarding Tiburon, there is one road into town. You go to Tiburon, they got your plate. Tiburon is a bit of a tourist trap since the ferry to Angel Island is based there.

Some towns in Nevada routinely run every plate at the local motels. People on the run will often stay at some obscure motel in a desert town. So running plates en mass isn't anything new. But the police have the "color of authority." But private companies shouldn't be able to sell what data they obtain IF the camera is placed on public property.

Regarding license plate readers on private property, it is THEIR property. Property owners have rights. But I think a good law would be that the camera has to be marked, and a sign must be displayed if they release the plate numbers read to third parties. Berkeley requires signage if you have surveillance cameras on your property.

Lastly, may I point out that the security patrols around Groom Lake (Area 51) routinely drive on public roads without plates on their trucks. There are numerous photos on the internet showing this. If I am required to have a license plate, then the men in black, or in the case of Groom Lake secuirty, camo, should have plates as well.

@ bolded statement ...

I can see it now.... police chief tells community they installed new LPR's to monitor for criminals coming in and out of town. AND, the good news, it won't cost you, the citizens, a dime.

However, every time you pass it, it snaps your plate, pulls up your personal info, cross-ref's it with consumer products info db's, and then a targetted ad gets played over your radio or pulled up on the huge electronic billboard next to the street....

"Hey BOB JOHNSON! Are you tired of your erectile dysfunction!? Then try new (insert product here)! And while you're at it, try new (insert product) for your jock itch!"

If a license plate is not on the hot-list, not a stolen car, not associated to any criminal reports, not related to any known terrorist activity, not associated with any outstanding police issues, and not related to illegal immigrants, why would it be stored in the police database? If it's clean, dump the data as it is completely irrelevant to the business of police, which is track down criminal activity.

It's not just about the crime you committed yesterday.

It's about the crime you're committing right now, and any pre-crimes you will have had planned to have been committing in the future.

I'm not sure how similar the issues really are, but the first thing that came to mind for me regarding the use of LPR's as a justification for probable cause is the evolution of how IP addresses are argued to be identifying information regarding the person on the other end. There are of course the copyright cases and subpoenas that are initiated on the basis of an IP address, followed by the presumption by some that the IP address then identifies a person. In the LPR case, there is the presumption that a license plate identifies the person in the vehicle.

1. Legally, a team of agents can follow you around in public and record your every move. Our new networked sensors and databases are the same thing, just more efficient. Therefore we should be allowed to record everything that everyone does in public.

2. If you videotape one of us in public we will confiscate your camera and arrest you.